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THE 


ART    OF    SAW-FILING, 

SCIENTIFICALLY  TREATED  AND  EXPLAINED 
ON  PHILOSOPHICAL  PRINCIPLES. 


rULL    AND    EXPLICIT    DIRECTlONg   FOR    PUTTING    IN     ORDEB 

ALL  KINDS  OF  SAWS,  FROM  A  JEWELLER's 

SAW  TO  A  STEAM  SAW-MILL. 


ILLUSTRATED  BY   FORTY-FOUR  ENGRAVINGa 


H.    -W,    II011.il. Y, 

AirxHOB  OP  "the  caepentee's  and  joineb's  hand-book." 


THIRD    EDITIO: 


NEW  YORK: 
JOHN    WILEY    &    SON- 
IS  ASTOR  PLACE. 

1871. 


^•<v.-    OP  rEr;^'^^ 


^i> 


^A 


Entered,  according  to  Act  of  Congress,  in  the  year  1S64,  ay 
JOHN    WILEY, 

In  the  Clerk's  Office  of  the  District  Court  of  the  United  States  for 
the  Southern  District  of  New  Yorli. 


B.    CRAIGHEAD, 
Frinier,  Siereotyper,  Hiid  Electrotyper, 

Cavton   ISuiltiing, 

81,  83,  o-  rf  i5  Cmire  3lre*L 


CONTENTS. 


PAGB 

Origin  and  utility  of  the  saw 7 

First  saw-mills  erected 9 

Principle  of  the  construction  of  the  saw 9 

Principle  of  the  cross-cut  saw 12 

Different  bevels  of  teeth 13 

Cross-cut  saw  for  soft  wood 15 

Cross-cut  saw  for  medium  wood 17 

Cross-cut  saw  for  hard  wood 18 

Pitch  of  the  teeth 18 

Cross-cut  timber-saw 24 

Back-saws  for  soft  wood 25 ' 

Back-saws  for  hard  wood 26 

The  fleam-tooth  saw 26 

Billet  or  buck-saws 27 

Billet  or  buck-saws  for  hard  wood 27 

The  too  common  saw 2S 

Long  cross-cut  or  log-saw 28 

Patent  hook-tooth  saw 29 

Cross-cut  circular-saws 30 

Cross-cut  circular-saws  for  soft  wood 32 

Cross  cut  circular  saws  for  hard  wood 33 

Pruning-saws 32 


IV  CONTENTS. 

PAOI 

Scroll,  web,  and  compass-saws 33 

Butchers'  saws 34 

Surgeons'  saws 35 

Hack-saws,  for  sawing  iron,  brass,  etc 36 

Principle  of  the  rip-saw 36 

Hand  rip-saws 37 

Vertical  mill-saws 40 

Circular  rip-saws 45 

Difference  of  teeth  for  circular-saws 46 

Explanation  of  the  division  of  a  circle  into  degrees 48 

Saw-setting 60 

The  Aiken  set 53 

The  crotch-punch  set 55 

Principle  of  the  Aiken  set 54 

The  old  way  of  setting  saws 56 

Selection  of  saws  and  other  tools 66 


-■J';.-  • 


f?'^  Of  TBE    '"4^ 

OTXVBESITYl 

THE 

ART  OF  SAW-FILING. 


ORIGIN  a:n'd  utility  of  the  saw. 

The  Saw  is  an  instrument  of  somewhat  an- 
cient origin.  "We  cannot  ascertain  precisely 
wlien  the  first  saw  was  made ;  but  it  probably 
followed  the  more  common  and  primitive  tools 
— the  hatchet,  the  knife,  and  the  chisel.  The 
first  saw  was,  no  doubt,  a  very  imperfect  instru- 
ment in  comparison  to  those  of  the  present  day. 
Still,  it  seems  incredible  that  such  elaborate 
works  of  art  as  we  read  of  among  the  ancients 
should  have  been  constructed  without  the  use 
of  the  saw. 

The  Greeks  ascribed  the  invention  of  the 
saw  to  Doedalus,  or  his  pupil  Talus ;  but  it  is 
certainly  more  ancient,  for  it  is  represented  on 
the  obelisks  of  Egypt.    It  is  a  tradition  that 


8  THE  ART  OF  SAW-FILING. 

the  prophet  Isaiah  suffered  martyrdom  by  tha 
saw. 

There  is  an  ancient  book,  called  the  "  As- 
cension of  the  Prophet  Isaiah."  It  says  : 
"  Then  they  seized  and  sawed  Isaiah  the  son 
of  Amos  with  a  wooden  saw.  And  Manasseh 
and  Melakira  the  false  prophets,  the  princes 
and  the  people,  stood  looking  on.  But  Isaiah 
said  to  the  prophets  who  were  with  him,  '  go 
ye  to  the  cities  of  Tyre  and  Sydon,  for  the  Lord 
hath  mixed  this  cup  for  me  alone.'  Neither 
did  he  cry  out  or  weep,  but  continued  to  call 
on  the  holy  ghost  until  he  was  sawn  asunder." 

It  may  be  in  reference  to  this  circumstance 
that  St.  Paul  says  of  the  early  martyrs,  "  They 
were  sawn  asunder." 

The  ark,  the  temple  of  Solomon,  and  the 
ruins  of  buried  cities  lately  exhumed,  would 
seem  to  have  been  impossible  without  the  use 
of  the  saw,  although  we  know  how  much 
may  be  accomplished  with  very  rude  tools 
when  time  and  patience  are  not  spared. 

We  do  not  find  the  saw  used  by  savage  na- 
tions, as,  without  the  tools  and  skill  to  keep  it 
in  order,  it  soon  becomes  useless. 


THE  ART  OF  SAW-FILINa.  9 

The  knife  and  the  hatchet,  more  barbarous 
weapons,  can  be  sharpened  on  a  smooth  stone ; 
but  sharpening  a  saw  is  a  very  different  affair. 

The  first  saw-mill^  or  saw  driven  bj  power, 
which  we  have  any  account  of,  was  erected  in 
the  Island  of  Madeira  in  1420 ;  the  next  at 
Breslau,  in  Austria,  in  1432.  This  was  fol- 
lowed bj  many  others  all  over  Europe. 

The  saw  is  now  an  indispensable  instrument, 
and  is  in  more  general  use  by  all  classes  of 
mechanics  than  any  other  tool. 

It  is  difficult  to  imagine  how  we  could  dis- 
pense with  it  for  a  single  day — from  the  burglar 
who  cuts  off  the  bars  of  his  cell  with  his  watch- 
spring  saw,  to  the  builders  of  navies  and  cities, 
and  the  busy  mills  which  quickly  fashion  the ' 
huge  monarchs  of  the  forest  into  shapes  for  the 
dwellings  and  conveniences  of  mankind. 

THE  PEmCIPLE  OF  CONSTEUCTIOK 

The  saw  is  a  series  of  knives  set  on  a  line; 

every  tooth  is  a  knife,  and  cuts  a  small  portion 

_  of  the  material.     Each  is  kept  from   cutting 

too  deep  by  the  tooth  on  either  side ;  each  tooth 

1* 


10  THE  ART  OF  SAW-FILING. 

shoula  cut  its  allotted  chip  or  slice  of  the 
material,  carry  it  along,  and  drop  it  on  the 
outside. 

The  perfection  of  a  saw  is  to  cut  the  fastest 
and  smoothest,  with  the  least  expenditure  of 
power.  To  do  this,  it  is  evident  that  each  and 
every  tooth  should  be  so  constructed  as  to  do 
its  own  proportion  of  work ;  for  if  one  tooth 
only  is  out  of  shape  or  out  of  line  with  the 
others,  it  is  not  only  useless,  but  a  hindrance 
and  disadvantage  to  the  others. 

Every  one  who  has  occasion  to  use  a  saw 
knows  that  many  times  it  would  be  very  con- 
venient if  he  knew  how  to  put  his  own  saw  in 
order.  To  be  sure  to  excel  in  this,  as  in  every- 
thing else,  requires  practice,  a  correct  eye,  and^ 
steady  hand.  But  we  contend  that  any  person 
of  ordinary  capacity  can  easily  learn  to  file  and 
set  his  own  saw. 

There  never  has  been  any  theory  or  prin- 
ciple laid  down  by  any  good  authority  for  this 
particular  science.  Each  person  has  had  a 
theory  of  his  own,  and  followed  that ;  or,  more 
likely,  has  had  no  theory  at  all,  and  did  it  at 
random,   sometimes   one  way  and  sometimes 


THE  AET  OF  SAW-FILI^^a  11 

another,  never  twice  alike,  but  generally  very 
unsatisfactorily  to  himself  and  all  concerned. 

Now  there  is  always  a  right  and  a  wrong 
way  to  do  anything ;  and  if  we  can  establish 
a  theory  in  this  little  book,  and  demonstrate 
its  correctness  from  scientific  principles,  and  a 
trial  shall  corroborate  the  demonstrations,  then 
the  object  of  the  author  will  have  been  accom- 
plished. 

We  find  many  very  good  mechanics  that 
have  always  used  saws,  who  frankly  acknow- 
ledge that  they  never  could  file  a  saw  satis- 
factorily to  themselves,  at  least.  The  rea- 
son probably  is,  they  never  studied  the  prin- 
ciple of  the  action  or  working  of  the  in- 
strument. There  is  no  reason  why  any  man. 
who  knows  enough  to  use  a  saw,  should  not 
be  able  to  put  it  in  complete  order;  although 
it  is  more  of  a  science  than  many  imagine — the 
putting  in  order  of  all  kinds  of  saws,  from  the 
delicate  surgeon's  saw  with  which  he  takes  off, 
your  limb,  to  the  monster  six-footer,  with  teeth 
like  a  dragon,  that  screams  in  the  depths  of  the 
forest,  devouring  trees  and  logs  with  insatiate 
rapacity. 


12  THE  ART  OF  SAW-FILING. 

"When  "we  consider  that  there  are  nearly  one 
hundred  different  kinds  of  saws  of  all  sizes  and 
shapes,  it  will  not  appear  strange  that  we  claira 
for  saw-filing  a  place  among  the  sciences. 

It  is  astonishing  what  miserable  saws  are 
sometimes  used  bj  mechanics,  or  those  claim- 
ing to  be  such.  The  only  way  they  can  be 
coaxed  or  driven  through  the  wood  is  by  hav- 
ing an  enormous  set,  a  liberal  use  of  oil,  and 
another  lubricator  called  elbow-grease.  The  dif- 
ference between  the  work  of  one  of  these  saws 
and  one  in  proper  order  is  about  the  same  as 
that  between  a  hole  bored  by  a  sharp  auger 
and  one  gnawed  by  rats. 

It  brings  to  mind  the  remark  of  the  wood- 
sawyer,  who,  puffing  and  blowing  from  the 
exertion  of  using  a  bad  saw,  said :  "  Of  all  the 
saws  I  ever  saw  saw,  I  never  saw  a  saw  saw  as 
this  saw  saws." 

Principle  of  the  Action  of  the  Oross-Cut  Sato. 

There  are  several  different  ways  in  which 
saws  act  in  relation  to  the  material  cut;  the 
first  we  shall  consider  is  the  cross-cut  saw,  by 
which  we  mean  all  saws  that  cut  across  the 
grain.     This  is  illustrated  by  the  figure. 


THE  ART  OF  SAW-FILING.  13 


Fig.  1. 

Fig.  1  represents  a  log  of  wood  seen  end- 
wise, looking  at  the  ends  of  the  grain,  which 
consists  of  more  or  less  minute  fibres  or  threads 
which  constitute  the  tenacity  of  the  wood. 

Our  object  with  the  cross-cut  saw  is  to  sever 
these  fibres  or  threads ;  and  as  the  material  is 
non-elastic  or  unyielding,  we  must  cut  each 
fibre  in  two  twice,  so  as  to  leave  a  small  groove 
or  Icerf  as  we  proceed,  so  that  the  material  will 
not  bind  or  pinch  as  the  saw  passes  through 
the  stick,  owing  to  any  inequalities  in  the 
blade  of  the  saw. 

Fig.  2  represents  a  section  of  several  saw- 


Fig.  2. 

teeth  of  different  bevels,  showing  the  different 


14  THE  AET  OF  SAW-FILING. 

depth  to  which  each  tooth  cuts.  The  next 
tooth  to  each  of  these  on  the  saw  being  bevel- 
ed the  other  way,  will  cut  to  the  same  depth, 
and  form,  a  groove  as  deep  as  the  teeth  reach 
into  the  wood,  and  so  on  in  succession  ;  each 
pair  of  teeth  working  independently,  except  as 
they  keep  each  other  from  taking  too  deep  a 
hold. 

A  saw  should  be  filed  so  truly 
that  it  will  show  an  angular  groove 
along  its  whole  length  on  the  edge 
like  Fig.  3,  so  that  a  fine  needle  will 
slide  the  whole  length  of  the  saw 
without  falling  off. 
Fig.  3.        Althoufrh  the  form  of  the  edf^e  of 


"If 


m 


Fig.  4.  Fig.  5. 

the  saw  is  like  Fig.  3,  it  must  cut  the  groove 
square  like  Fig.  4  and  not  like  Fig.  5,  the 
shape  of  the  saw's  edge. 

The  cutting  is  all  done  with  the  outside 
edge  of  the  tooth,  so  the  real  operation  of  the 
tooth  is  like  Fig.  6 ;  the  wood  crumbling  out 


THE  ART  OF  SAW-FILING.  15 


Fig.  6. 

from  point  to  point  of  each  tooth  as  the  saw 
moves. 

Now  the  sharper  each  tooth  is — that  is,  the 
more  bevel  on  the  point,  as  shown  at  Fig.  2, 
the  deeper  it  will  cut;  but  it  must  not  cut 
any  deeper  than  will  crumble  out  across  to  the 
point  of  the  other  tooth.  This  is  the  difference 
between  saws  for  soft  or  hard  wood  ;  if  a  saw 
for  hard  wood  is  too  much  bevel  on  the  point, . 
it  will  score  deeper  into  the  wood  than  it  can 
carry  out  the  chip,  so  that  it  will  keep  moving 
up  and  down  in  the  same  scores,  and  not 
accomplish  anything. 

It  follows,  then,  that  for  soft  wood  we  may 
file  the  back  edge  or  point  of  the  tooth  quite 
beveling,  while  the  harder  or  tougher  the  wood 
the  less  bevel  we  must  file  the  back  of  the 
tooth ;  for  we  shall  see  that  the  bevel  of  the 


16 


THE  ART   OF  SAW-FILING. 


back  of  the  tooth  governs  the  bevel   of  the 
point. 

Let  it  be  understood  that  the  bevel  of  the 
cutting  edge  of  the  tooth  is  the  same  for  all 
cross-cut  saws.  The  level  of  the  i^oint  is  the 
idea,  and  is  governed  by  the  angle  at  which 
the  file  is  held.  This  is  illustrated  by  the  fol- 
lowing figures. 


Fig.  7. 

%  Fig.  Y,  shows  the  position  of  the  file  for  a 
-j^oss-eut  saw  for  soft  wood,  such  as  pine,  bass- 
wood,  cedar,  etc. 

h  Shows  the  shape  of  the  tooth,  and  c  the 
Devel  of  the  point,  consequent  on  the  posi- 
tion of  the  file  and  bevel  of  the  back  of  the  tooth. 


THE  ART  OF  SAW-FILING. 


17 


There  is  no  difference  in  th6  angle  of  a  large 
or  small  file ;  all  the  difference  is  in  the  fine  or 
coarse  cut  of  the  file.  We  should  prefer  a 
good  sized  file,  not  less  than  fourand  a  half  or 
five  inches,  if  it  was  cut  equally  fine  and  sharp 
on  the  corners. 

In  all  the  following  diagrams  of  saw-teeth, 
the  point  of  the  saw  is  supposed  to  be  on  the 
left  hand. 


Fig.  8. 

a,  Fig.  8,  shows  the  position  of  the  file  for 
Baws  for  medium  wood,  such  as  chestnut,  bay- 
wood,  black  walnut,  cherry,  etc. ;  b  shows  the 
shape  of  the  tooth,  and  c  the  bevel  of  the 
point. 

a,  Fig.  9,  shows  the  position  of  the  file  for 


18 


THE  ART  OF  SAW-FILING. 


Fig.  9. 

saws  for  hard  wood,  such  as  hickory,  ash,  oak, 
maple,  beech,  etc. ;  h  shows  the  shape  of  the 
tooth,  and  c  the  bevel  of  the  point. 

It  will  be  seen  that  the  bevel  on  the  pitch  or 
cutting  edge  of  the  tooth  is  the  same  in  all  the 
above  examples ;  but  the  bevel  of  the  point 
looking  the  length  of  saw  is  quite  different. 

The  next  thing  to  be  considered  is  the  angle 
of  the  pitch  or  cutting  edge  of  the  tooth  of  a 
cross-cut  saw. 

Let  a.  Fig.  10,  represent  a  board,  across 
which  we  wish  to  make  a  deep  mark  or  score 
with  the  point  of  the  knife.  Suppose  we  hold 
the  edge  of  the  knife  perpendicular,  as  at  5,  it 
is  evident  that  it  will  push  harder,  will  njt  cut 


THE   ART  OF  SAW-FILIXG. 


19 


VvV 


50  deep  or  so  smooth  as  if  it  was  inclined  for- 
ward, as  at  a. 

It  follows  tliat  tlie  cutting  edge  of  a  tooth 
should  incline  forward,  like  that  at  c,  rather 
than  stand  perpendicular,  as  at  d. 

This  is  a  common  fault  with  cross-cut  saws, 
making  the  teeth  too  hooking,  as  it  is  called. 
The  idea  is  that  the  saw  takes  hold  better. 
This  may  be  true,  but  it  will  be  like  the  man's 
razor  that  took  hold  first-rate,  but  didn't  let  go 
worth  a  cent. 

Having  considered  the  bevel  of  the  cutting 
edge  of  the  tooth,  the  bevel  of  the  point  in 


20  THE    ART  OF   SAW-FILING. 

relation  to  the  material  to  be  cut,  also  the  pitch 
or  inclination  of  the  cutting  edge — if  we 
combine  all  these  we  shall  have  a  perfect 
tooth. 

It  will  be  seen  by  Figs.  7,  8,  and  9,  that  we 
hold  the  point  of  the  file  towards  the  point  of 
the  saw.  Many  will  contend  that  a  saw  should 
be  filed  towards  the  handle,  giving  as  a  reason 
that  it  prevents  the  feather  on  the  cutting  edge 
of  the  tooth.  This  feather  edge  is  no  objec- 
tion, for  every  saw  after  filing  should  be  laid 
down  flat  and  both  sides  jointed  or  planed 
down,  so  that  the  cut  of  every  tooth  shall  be 
exactly  on  a  line. 

This  should  be  done  with  a  long  whetstone, 
or  fine-cut  file  with  straight  sides.  This  takes 
off  all  the  feather,  makes  a  finer  edge  and 
more  cutting  surface ;  for  if  a  saw  is  newly 
set,  and  not  jointed  on  the  sides  after  filing  as 
above,  all  the  cutting  surface  is  the  extreme 
point  of  the  tooth,  which  only  scratches  and 
does  not  cut ;  it  is  like  marking  across  a  board 
with  the  point  of  a  pin. 

a,  Fig.  11,  shows  the  point  of  the  tooth  as 
it  is  left  after  filing ;  h  is  the  same  Doint  after 


THE  ABT  OF  SAW-FILING. 


21 


rig.  11. 
jointing   the  sides,  making  a  real  knife-edge, 
and  not  a  mere  scratching  point. 

And  further,  as  regards  filing  towards  the 
point  of  the  saw.  We  cannot  any  other  way 
get  the  bevel  of  the  teeth,  as  shown  at  Figs. 
7,  8,  and  9,  as  will  readily  be  seen ;  and  still 
farther,  every  one  knows  how  much  stiller, 
smoother,  and  with  less  vibration  the  file  runs 
when  filed  towards  the  point  of  the  saw. 

Tlie  Cross-Cut  Hand-Saw, 

This  saw  is  more  common  and  in  more 
general  use  than  any  other  saw.  They  are  of 
various  lengths,  from  twelve  to  thirty-two 
inches. 


Fig.  12. 


22  THE  AET  OF  SAW-FILINft. 

This  saw  for  soft  wood  should  have  about 
six  teeth  to  the  inch,  and  be  filed  about  the 
bevel  shown  in  Fig.  12. 

Give  the  teeth  a  full  set,  and  joint  the  sides 
thoroughly. 

We  would  say  here  that  the  first  thing  to 
be  done  in  filing  these  saws  is  to  see  that 
they  are  perfectly  straight  on  the  edge,  or,  if 
anything,  a  little  the  highest  in  the  middle. 
This  is  very  important ;  for  if  any  tooth  is 
shorter  than  the  rest,  of  course  that  tooth  does 
not  cut  at  all,  and  is  worse  than  useless,  for  it 
gives  the  next  tooth  more  than  its  share  of  the 
work  to  do,  and  consequently  it  is  imperfectly 
done. 

Place  the  saw  in  the  clamp,  and  with  a  fine 
single-cut  file,  not  less  than  ten  inches  long, 
file  the  teeth  squarely  down  till  every  one  is 
touched.  Next  comes  the  setting ;  the  princi- 
ple of  setting  and  the  best  set  will  be  consi- 
dered hereafter.  Vj\j^.t  tUOtL  P^qt  ^o  t^ 

See  that  every  tooth  is  bent  to  the  full 
capacity  of  the  set,  for  some  of  the  teeth  that 
are  filed  off  a  good  deal  in  jointing,  will  want 


THE  ART  OF  SAW-FILING.  23 

a  mucli  harder  blow  than  those  that  are  only 
just  touched. 

The  saw  should  be  placed  in  a  strong  light, 
so  that  it  will  be  easy  to  see  when  every  tooth 
is  brought  to  a  point. 

Be  careful  and  not  give  a  single  stroke  of 
the  file  after  the  tooth  is  brought  to  a  point ; 
that  would  be  worse  than  useless.  If  you  can- 
not get  the  right  shape  of  every  tooth  in  an 
old  saw  without  filing  too  much,  let  it  be  till 
next  time.  It  is  better  to  let  the  imperfect 
tooth  wait  its  time,  than  to  spoil  a  perfect  one 
in  trying  to  make  it  correspond  with  the  im- 
perfect one. 

Cross-  Cut  Hand-Saw  for  Medium  Wood, 


Fig.  18. 

This  saw  should  have  about  eight  teeth  to 
the  inch,  and  the  bevel  shown  in  Fig.  13. 
This  is  about  the  thing  for  miterinor  soft  wood 


24 


THE   AET  OF  SAW-FILING. 


-a 


that  is,  the  bevel.  The  teeth  may  be  as  coarse 
as  Fig.  12. 

It  will  pay  to  have  a  different  saw  for  diffe- 
rent kinds  of  work,  both  in  wear  and  tear 
of  patience,  and  excellence  of  workmanship. 
Those  who  attempt  to  do  all  kinds  of  work 
with  the  same  tool,  will  find  most  of  the  time 
that  they  have  not  the  right  kind  of  tool  for 
any  work. 

Cross-  Oat  Hand-Saw  for  Hard  Wood. 


Fig.  14. 

This  should  have  ten  teeth  to  the  inch,  and 
the  back  of  the  tooth  filed  square.  It  will 
mitre  soft  or  medium  wood  well.  The  bevel 
on  the  pitch  of  all  these  saws,  it  will  be  seen, 
is  the  same.  The  difference  is  in  the  sharpness 
of  the  bevel  on  the  points 

Cross- Out  Timher-Saw. 

This  should  have  four  teeth  to  the  inch,  and 


THE  ART  OF  SAW-FILING. 


25 


filed   about    like  Fig.  13,   and   should  have 
plenty  of  set  for  wet  pine  or  spruce  timber. 
\    Back-Saws. 

A  back-saw  has  no  advantage  over  a  hand- 
saw, except  in  the  thinness  and  lightness  of 
the  plate  ;  the  back  keeping  it  from  spring- 
ing or  bending. 

They  should  be  thinner  on  the  back,  so  as 
to  need  no  setting. 


rig.  IB. 

Fig.  15  shows  the  kind  of  back-saw  for  soft 
wood,  ten  teeth  to  the  inch,  same  bevel  aa 
Fig.  12. 


26  THE   ART  OF  SAW-FILING 

Fig.  16  is  the  back-saw  for  hard  wood, 
twelve  toeth  to  the  inch.  Same  bevel  as  Fig. 
14.     Eight  for  mitering  soft  or  medium  wood. 

Sometimes  a  back-saw  becomes  crooked 
because  the  back  is  loose ;  if  so,  driving  the 
back  on  firmly  will  straighten  it  again. 

The  Fleam-Tooth  Saw, 


Fig.  IT. 

This  saw  is  filed  extremely  beveling,  so 
much  so,  that  the  saw  must  be  laid  down  flat 
to  be  filed.  ISTo  set  is  needed,  and  the  blade 
must  be  thin  and  of  the  best  quality  and  tem- 
per of  cast  steel. 

The  best  way  to  alter  an  old  saw  to  one  of 
these,  is  to  take  off  the  old  teeth  clean,  and 
bef^in  new. 


THE  ART  OF  SAW-FILING. 


27 


Fig.  17  shows  the  form  of  tooth,  fall  size, 
and  the  position  of  the  file  and  saw. 

This  saw  is  only  fit  for  soft  and  clear  wood, 
the  edges  being  so  thin  that  a  knot,  or  hard 
wood,  spoils  them.  It  is  very  nice  for  trim- 
ming or  clap-boarding,  cutting  very  fast  and 
smooth,  and  both  ways  alike. 

Billet  Wood-cutters',  or  Buck-Saws. 


Fig.  la 


Fig.  18  shows  the  buck-saw  for  soft  or  green 
wood ;  four  teeth  to  the  inch,  strong  set,  well 
jointed  on  the  sides. 

Buch-Saws  for  Hard  Wood. 


Pig,  19. 


28  THE  ART   OF  SAW-FILING. 

Fig.  19  is  tlie  buck-saw  for  hard  or  dry 
wood,  five  or  six  teeth  to  the  inch ;  teeth 
square  on  the  back. 

Buck-saws  should  be  well  strained  up,  so  as 
to  ring  sharp  and  clear  when  struck. 

The  Too  Common  Saw. 


Fig.  «0. 

Fig.  20  shows  the  kind  of  saw  too  common 
to  need  a  description.  It  is  used  in  all  parts 
of  the  country.  We  cannot  recommend  its 
adoption. 

Long  Gross-  Cut  or  Log-Saw. 

This  saw  is  to  cut  equally  both  ways,  con- 
sequently the  shape  of  the  teeth  must  be  dif- 
ferent from  anything  we  have  seen.  This  saw 
on  the  tooth  edge  is  made  the  segment  of  a 
large  circle  or  ellipse,  because  the  motion 
easiest  for  two  men  in  sawing,  is  a  rocking  or 


THE   ART   OF  SAW-FILING. 


29 


Fig.  21. 

swaying  motion,  bringing  all  the   teeth   suc- 
cessively into  action. 

For  hard  and  dry  wood,  file  the  teeth  less 
bevel ;  see  that  every  tooth  is  in  line  with  the 
others,  whether  the  line  is  more  or  less  curved. 

The  Patent  Hook-Tooth  Cross- Cut  Saw.^ 
3  a  I 


Fig.  22. 
♦  Manufactured  by  Wheeler,  Madden  and  Clemson,  Middle  town,  N.T: 


BO  THE  ART  OF  SAW-FILING. 

This  saw  is  constructed  on  common  sense 
principles.  The  two  knives  or  fleams,  a,  to 
score  into  the  wood ;  5,  the  hook  or  little  chisel,* 
follows  and  takes  out  the  chip  or  shaving, 
carries  it  along,  and  drops  it  on  the  outside. 
It  acts  precisely  like  a  carpenter's  "  dado  plane," 
only  it  acts  both  ways.  The  action  of  the 
centre-bit  also  illustrates  the  principle  of  this 
saw. 

It  cuts  very  fast  and  easy,  and  is  said  to  be 
rapidly  superseding  the  old  kinds  in  the  loca- 
lities where  it  has  been  introduced. 

The  cutting  teeth,  a,  are  first  filed  up  square, 
and  the  hooks,  5,  are  left  nearly  a  sixteenth 
shorter.  After  the  length  of  the  cutters  and 
hooks  is  made  just  right,  file  the  cutters  ex- 
tremely beveling,  but  bring  them  to  an  edge 
only  at  the  extreme  point  of  the  tooth,  and 
then  not  so  as  to  leave  a  feather. 

Cross- Cut  Circular  Saws. 

The  same  rule  holds  good  in  regard  to  the 
bevel  and  pitch  of  the  tooth  in  the  circular 
saw  as  in  the  hand-saw.  The  fibre  or  grain  of 
the  wood  to  be  divided  is  always  at  right 
angles  to  the  face  of  the  saw. 


THE  ART  OF  SAW-FILING. 


31 


Fig.  28. 

To  get  the  proper  pitch  of  the  tooth  of  this 
saw,  describe  a  circle  whose  diameter  is  one 
quarter  the  diameter  of  the  saw ;  a  line  from 
the  point  of  the  tooth  touching  the  outside  of 
this  circle,  as  shown  in  Fig.  23,  will  give  the 
proper  pitch  of  the  tooth. 


Fig.  24. 


82  THE  ART  OF  SAW-FILIKG. 

Fig.  24  shows  the  proper  form  of  tooth  for 
a  large  circular  saw,  for  large  sticks  of  soft  or 
green  wood. 


Fig.  25, 

Fig.  25  shows  the  form  of  teeth  for  hard 
and  dry  wood.  The  points  may  be  more  bevel 
than  for  hand-saws.  The  greater  velocity  of 
the  circular  saw  will  throw  out  the  chip. 

Observe  the  same  rules  for  small  circular 
saws  for  finer  work  as  for  hand-saws  at  Figs. 
12,  13,  and  14. 

Pruning  Saws. 

These  are  required  to  cut  very  smooth  and 
keen,  consequently  the  teeth  must  have  a  good 
deal  of  bevel,  but  about  the  same  pitch  as  an 
ordinary  cross-cut.     Fig.  26  shows   the  best 


THE  ART  OF  SAW-FILING.  33 


Fig.  26. 

form  of  a  pruning  saw,  seven   teeth   to  the 
inch. 

These  saws  are,  or  should  be,  made  thin  on 
the  back,  so  as  to  require  no  setting ;  but  must 
be  well  rubbed  or  jointed  on  the  sides  to  take 
off  the  feather  edge  made  in  filing. 

Scroll^  Wehj  and  Compass  Saws. 

These  saws  are  for  a  mixed  business.  They 
have  in  turn  to  cross-cut,  mitre,  and  rip,  and 
the  question  is,  what  is  the  best  average  or 
medium  to  accommodate  all  these  require- 
ments. 

Experience  shows  that  they  should  be  nearer 
the  cross-cut  than  the  rip,  for  a  cross-cut  will 
rip,  better  than  a  rip  will  cross-cut.  A  rip-saw 
makes  terrible  rough  work  cutting  across  the 
grain,  while  a  regular  cross-cut  will  cut  length- 
wise of  the  grain  smooth  but  slower. 
2* 


34  THE  ART  OF  SAW-FILING. 

^i^N^N^N^N^i 


Fig.  27. 

Fig.  27  shows  the  proper  form  of  tooth  for 
these  saws,  though  thej  maj  be  finer  or 
coarser  according  to  the  material  to  be  cut; 
finer  teeth  for  hard  wood. 

Rather  a  short  bevel  on  the  pitch,  which 
should  be  a  little  less  than  a  right  angle.  All 
web  saws  should  be  ground  thin  on  the  back, 
so  as  to  require  no  setting. 

Butcher  Saws. 

These  are  for  sawing  bones,  and  generally 
very  hard  and  dense  ones.  Cutting  these  is 
out  of  the  question,  so  that  this  saw  should 
partake  more  of  the  nature  of  the  file.  The 
form  shown  in  Fig.  28  is  the  best  for  this  saw. 

The  pitch  should  be  not  less  than  an  angle 
of  forty-five  degrees,  and  the  back  the  same, 
or  nearly  so. 

File  the  teeth  perfectly  square  across  on  the 
pitch  and  on  the  back. 

Be  yerj  particular  about  jointing  the  edge, 


THE  AET  OF  SAW-FILING.  85 

AAA^AA^^A^vA^^^vvV^^^^ 


Fig.  23. 

SO  tliat  every  tooth  shall  do  its  work.  It  need 
not  be  jointed  on  the  sides. 

Surgeons'  Saws. 

These  must  be  filed  somewhat  different  from 
the  Butchers'  saw,  though  some  people  clasa 
surgeons  and  butchers  in  the  same  category. 

The  human  bone  in  a  living  body  is  some- 
what porous  and  soft,  consequently  the  pitch 
of  the  tooth  may  be  somewhat  sharp.     Make 


AA^^^^^^\^ 


Fig.  28. 


S6  THE  ART  OF  SAW-FILING. 

the  teeth  about  the  same  shape  as  Fig.  28,  hu\ 
about  the  bevel  in  Fig.  29,  the  back  being 
square. 

Joint  these  on  the  side,  as  it  is  important  to 
have  the  bone  left  perfectly  smooth  and  clean. 

ffuch-jSaws,  for  sawing  Irorij  Brass^  etc. 


,  Fig.  80. 

These  should  be  the  same  as  Fig.  28,  as 
regards  shape  of  tooth,  pitch,  and  bevel,  but 
the  teeth  should  be  as  fine  as  possible ;  for,  as 
was.  said  of  Fig.  28,  they  must  partake  more 
of  the  nature  of  the  file ;  in  fact,  they  are  no 
more  or  less  than  a  thin  file,  cut  on  the  edge 
but  not  on  the  side.  These  need  not  be  joint- 
ed on  the  sides. 

The  Rip  or  Slitting-Saw. 

Having  considered  the  principle  of  the 
cross-cut  saw,  we  learn  that  its  action  in  rela 
tion  to  the  material  cut  is  the  same  in  all  cases, 
that  is,  the  grain  of  the  wood  is  always  at 
right  angles  to  the  face  of  the  saw 


THE  ART   OF  SAW-FILING. 


37 


In  the  action  of  the  rip-saw  it  is  quite  dif- 
ferent. There  are  three  kinds — the  hand-saw, 
the  vertical  or  mill-saw,  and  the  circular-saw 
These  all  act  differently  in  relation  to  the  ma- 
terial cut,  that  is,  cut  their  way  into  the  wood 
on  a  different  angle  from  the  direction  of  the 
fibre  or  grain  of  the  wood. 

The  Hand-Saiu, 


1 


7 


Fig.  31. 


a,  Fig.  31,  shows  the  correct  form  of  tooth 


38  THE  ART  OF  SAW-FILING. 

for  a  rip-saw  for  straight-grained  stuff.  It  will 
be  seen  that  each  tooth  is  a  small  chisel,  paring 
a  regular  shaving,  and  leaving  a  groove  behind 
it  the  width  of  the  chisel  or  tooth,  h  shows 
the  actual  form  and  direction  of  the  point  and 
shaving.  It  is  easy  to  imagine  the  ease  with 
which  such  a  saw  would  pass  through  a  board 
lengthwise.  The  whole  being  a  succession  of 
sharp  chisels,  would  cut  through  a  board  with 
astonishing  rapidity.  The  chips  of  this  saw 
will  not  be  dust,  but  short  shavings. 


rig.  82. 


a,  Fig.  32,  shows  the  next  best  form  of  tooth 
or  a  hand  rip-saw.      l  shows  the  true  and 


THE  AKT  OF  SAW-FIIJNG.  89 

actual  angle  of  the  point  of  the  chisel  that 
does  the  cutting.  The  pitch  of  the  tooth  and 
the  line  of  the  points  give  the  true  angle  of  the 
cut,  and  not  the  pitch  and  the  hach  of  the 
tooth,  as  would  seem  to  be  the  case  at  first 
sight. 

We  see  a  great  difierence  between  the  cut- 
ting angle  of  this  tooth,  shown  at  5,  and  that 
at  Fig.  31. 

This  saw  will  work  very  well.  The  trouble 
is,  the  teeth  are  too  slender  at  the  points,  and 
are  apt  to  tremble  or  chatter,  especially  if  the 
saw  is  crowded  too  hard. 

For  straight-grained  stuff  this  saw  may  be 
filed  square  across,  but  as  we  are  sure  to  come 
more  or  less  in  contact  with  cross-grain  or 
knots,  it  is  best  to  file  the  pitch  of  the  tooth  a 
little  beveling.  For  soft  wood,  after  the  saw 
is  set,  hold  the  file  at  right  angles  to  the  saw, 
and  it  will  give  a  slight  bevel  to  the  points  of 
the  teeth. 

For  hard  wood  they  should  have  a  little 
more  bevel  stilL 


40  THE  ART  OF  SAW-FILING. 


Fig.  88. 

fly  Fig.  33,  shows  the  most  common,  ana  yet 
the  worst  form  of  tooth  for  a  rip-saw.  h  shows 
the  real  cutting  of  the  tooth,  and  the  absurdi- 
ty of  this  shape.  There  is  really  no  cutting 
about  it.  The  wood  is  merely  jammed  or 
scraped  out  with  a  very  unnecessary  expendi- 
ture of  power. 

It  seems  strange  that  workmen  will  persist 
in  using  this  kind  of  saw,  and  yet,  probably 
nine- tenths  of  the  saws  used  are  of  this  fash- 
ioned tooth. 

The  Vertical  Mill-Saw. 

There  are  three  different  forms  of  tooth  used 
for  the  vertical  mill-saw.  This  saw  must 
necessarily  run  perpendicularly,  and  therefore 


THE  AET  OF  SAW-FILING. 


41 


the  action  in  contact  with  the  grain  of  the 
wood  is  different  from  the  hand-saw. 

It  is  the  same  as  the  chisel  in  cutting  down 
the  head  of  a  mortise. 


Fig.  84 


a,  Fig.  84,  shows  the  correct  form  of  tooth 


42  THE  ART  OF  SAW-FILING. 

for  a  vertical  mill-saw ;  h  is  the  shape  of  the 
point  of  the  tooth  set  with  the  crotch-punch 
described  hereafter ;  c  shows  the  actual  shape 
or  action  of  the  cut  of  the  tooth. 

It  is  not  enough  that  a  saw  cuts  its  chip  or 
shaving.  There  must  be  space  enough  between 
the  teeth  to  hold  the  shaving  without  crowd- 
ing till  it  can  be  carried  outside  the  stick  and 
dropped. 

This  reason  alone  sometimes  causes  a  saw  to 
run  very  badly,  consequently  large  saws  have 
after  a  while  to  be  gummed,  or  more  space 
made  between  the  teeth. 

The  saw-dust  from  this  saw  will  be  in  square 
blocks,  like  the  chips  from  a  mortising  ma- 
china 


THE  ART  OF  SAW-FILING. 


43 


Fig.  85. 

a,  Fig.  35,  shows  the  next  best  form  of 
tooth  for  a  vertical  mill-saw ;  h  shows  the 
teeth  upset  on  one  side,  with  the  crotch-punch 
without  bending  the  tooth. 

This  saw  is  the  connecting  link  between  the 
old  and  new,  the  good  and  the  bad,  both  in 
setting  and  in  the  shape  of  the  tooth,  c  shows 
the  angle  at  which  the^Qhjp^  is  cut  from  the 


/f\>       OF  THT?     ^>^ 


-*\Vj;i 


44 


THE   ART  OF  SAW-FILING. 


end  of  tlie  wood.  It  is  plain  that  this  shape 
of  tooth  requires  more  power  to  cut  its  way- 
through  the  log  than  that  shown  at  Fig.  34. 

H 


Fig.  36. 

cr,  Fig.  36,  shows  the  old,  and  still  the  most 
common  shaped  tooth  for  mill-saws ;  b  is  f 
style  of  setting  or  bending  the  teeth  ;  c  shows 
the  cutting  angle  of  the  tooth.     The  sharp 
comer  soon  wears  off,  and  all  the  sawing  ia 


THE   ART   OF  AW-FILING. 


45 


done  bj  scraping  and  jamming  witk  a  great 
waste  of  power. 

Circular  JRip-Saios. 

The  circular   rip-saw  lias  a  still   different 


Fig.  37. 

action  in  regard  to  the  contact  of  the  teeth 
with  the  grain  of  the  wood. 

It  will  be  seen  by  the  figure  that  each  tooth 
has  a  different  bearing  on  the  grain  of  the 
wood  as  the  saw  revolves,  a  shows  the  log 
and  the  direction  of  the  grain  or  fibre  of  the 
wood.  It  will  be  seen  that  the  teeth  at  h  are 
cutting  almost  directly  on  a  line  with  the  grain, 
while  those  at  c  are  cutting  almost  at  right 
angles,  like  the  vertical  mill-saw. 

It  requires  much  more  power  to  cut  with 


46  THE  ART  OF  SAW-FILING. 

these  lower  teeth  than  with  the  top  ones.  Thig 
is  readily  proved  by  sawing  a  plank  with  a 
large  saw.  Baise  the  saw-table  till  the  saw 
just  cuts  through  the  top  of  the  plank,  and 
perhaps  the  saw  will  run  through  it  very 
easily ;  while  if  you  lower  the  table  so  that 
the  plank  will  run  as  close  to  the  centre  of  the 
saw  as  possible,  it  might  be  very  likely  to  stop 
the  saw,  while  it  cut  it  at  the  top  with  ease. 

Almost  every  one  who  uses  a  slitting-saw 
knows  this  fact,  though  perhaps  not  aware  of 
the  philosophy  of  the  difference.  It  is  merely 
the  difference  of  cutting  on  a  line  with  the 
grain  or  across  it,  of  whittling  a  stick  to  a  long 
point  or  cutting  it  square  in  two. 

We  find  three  kinds  of  teeth  in  circular  rip- 
saws, as  well  as  the  other  kinds  previously  de- 
scribed. We  should  style  them  as  good,  me- 
dium, and  bad. 


THE   AKT  OF  SAW-FILING. 


47 
f 


Fig.  38. 


Fig.  38  is  the  correct  and  proper  form.    Fig. 
39  will  do,  but  is  too  light  on  the  points,  caus« 


Fig.  89. 


ing  the  teeth  to  tremble  or  chatter ;  while  Fig, 


48  THE  ART  OF  SAW-FILING. 


7 


Fig.  40. 

40  is  the  old  scraper  of  wliicTi  we  "have  heard 
enough  already. 

Almost  any  form  of  tooth  can  be  driven 
through  the  wood  by  sheer  force,  but  if  power 
is  of  any  consequence,  we  shall  study  to  adopt 
that  kind  which  uses  the  least ;  a  circular-saw 
will  last  twice  as  long  if  made  in  the  new  way 
instead  of  the  old,  because  it  will  not  get  hot 
and  thus  warped  and  sprung  out  of  true  so 
often.  It  is  thought  by  good  judges  that  the 
pitch  of  the  tooth  of  a  slitting-saw  should  not 
be  less  than  an  angle  of  sixty  degrees. 

Perhaps  it  will  be  well  to  explain  here  what 
is  meant  by  an  angle  of  sixty  degrees. 

Every  circle,  large  or  small,  is  divided  into 
three  hundred  and  sixty  degrees  ;  a  degree  be- 


THE  ART  OF  SAW-FILING. 


4S 


ing  the  acuteness  of  the  angles  of  360  lines, 
radiating  from  the  centre  like  the  spokes  of 
a  wheel,  so  that  an  angle  of  sixty  degrees  is 
the  same  on  a  small  circle  as  a  large  one.  The 
actual  measurement  of  a  degree  on  the  outside 
of  a  circle  is  a  different  affair.  A  degree  on 
the  earth's  surface  is  sixty-nine  and  a  half 
miles. 

If  a  circle  is  360,  a  half  circle  is  180,  and  a 
quarter  circle  90  degrees.  All  we  want  for 
our  purpose  is  a  quarter  circle. 

90     80 


Fig.  41. 

Fig.  41  shows  a  half  circle  divided  into 
angles  of  ten  degrees  each.  Counting  from 
the  horizontal,  ninety  degrees  is  perpendicular, 
or  a  right  angle.     If  we  want  to  ascertain  the 


50  THE  AET   OF  SAW-FILING. 

angle  of  any  object  from  a  certain  line  we  call 
that  line  one,  and  ninety  degrees  from  that  is  a 
right  angle. 

When  the  sun  is  half  way  up  to  the  meri- 
dian, we  say  it  is  forty-five  degrees  high ;  when 
a  quarter  up,  we  say  it  is  twenty-two  and  a 
half  degrees  high,  from  the  horizon. 

To  return  to  the  saw,  we  want  the  pitch  of 
the  tooth  an  angle  of  sixty  degrees  from  the 
horizontal.  This  angle  will  form  an  equilate- 
ral triangle,  as  will  be  seen  by  the  figure. 

The  same  angle  is  formed  by  describing  a 
circle  whose  diameter  is  one  half  the  diameter 
of  the  saw,  and  drawing  a  line  from  the  point 
of  the  tooth,  across  the  outside  of  the  circle  as 
at  g.  Fig.  42. , 

Saw-Settmg.  ^  f^^^  f  22-^5 

This  is  an  important  p^^of  the  work  of 
keeping  a  saw  in  order ;  for  a  saw  may  be  filed 
very  scientifically,  and  if  badly  set  it  will  do  its 
work  very  poorly  or  not  at  all. 

The  object  of  setting  is  not  to  increase  its 
cutting  power,  for  a  saw  will  cut  faster  if  not 
set,  provided  it  will  pass  through  the  wood 
without  pinching  or  binding. 


I 


THE  ART  OF  SAW  FILING. 


61 


\^o/\ 


U.. 


FiR.43. 


62  THE  AET  OF  SAW-FILIXG. 

Many  saws  are  being  made  latterly,  ground 
thinner  at  the  back,  and  we  hope  this  practice 
will  prevail ;  for  if  a  saw  is  ground  thin  at  the 
back,  and  ground  even  and  regular,  and  filed 
scientifically,  it  will  need  no  setting.  Many  a 
saw  binds,  not  because  it  is  not  set  enough,  but 
because  it  is  filed  so  badly  that  it  cuts  ragged 
and  uneven,  leaving  the  groove  filled  up  with 
the  half-severed  fibres  of  the  wood,  like  sawing 
through  a  bale  of  cotton. 

The  first  consideration  in  setting  is  perfect 
uniformity.  This  is  indispensable.  The  next 
13  the  proper  form  of  bending  or  opening  the 
teeth. 

There  are  a  great  variety  of  saw-sets  invented, 
manufactured,  sold,  and  used  ;  some  are  good  ; 
a  great  proportion  are  good  for  nothing.  The 
old  wa}^  of  setting  with  a  punch  on  a  block  of 
wood,  is  very  far  from  the  right  way.  It  is 
impossible  to  strike  every  blow  alike,  and  the 
wood  being  the  fulcrum  over  which  the  tooth 
is  bent,  yields,  and  the  tooth  is  bent  clear  to  its 
base,  which  is  very  likely  to  kink  the  saw. 
One-third  of  a  tooth  is  all  that  should  be  set  or 
turned  out  of  line  of  the  blade. 


THE  ART  OF  SAW-FILING.  53 

A  correct  saw-set  should  be  so  constructed 
that  the  tooth  must  be  bent  just  far  enough, 
and  at  the  same  time  cannot  be  bent  too  far,  even 
by  repeated  blows.  On  a  good  piece  of  steel 
sometimes  one  blow  will  have  no  effect,  the 
tooth  springing  back  again ;  two  or  three  blows 
being  necessary  to  make  it  stay  where  it 
should  be. 

On  this  account  we  think  those  sets  that  act 
like  a  pair  of  plyers,  bending  the  teeth  with 
the  hand,  quite  objectionable,  not  being  able 
to  make  the  tooth  stay  set. 

If  one  or  two  teeth  in  a  saw  are  bent  too  far, 
they  only  scratch  and  make  the  work  rough 
and  waste  power ;  while  if  not  bent  far  enough 
they  do  nothing,  and  are  drones  in  the  hive. 

We  believe  the  best  saw-set  to  be  found  for 
ordinary  sized  teeth  is  that  known  as  the 
*'  Aiken  set,"  represented  by  Fig.  43, 


54 


THE  AET  OF  SAW-FILING. 


Fig.  43. 

Althougli  this  set  was  invented  manj  years 
ago,  it  has  never  been  superseded. 

Many  spurious  imitations  of  this  set  have 
been  manufactured  of  poor  material ;  so  it  be- 
comes the  buyer  to  be  careful  and  get  the  genu- 
ine ;  for  if  the  material  is  not  perfect,  they  are 
worse  than  none  at  all. 

We  believe  the  principle  of  this  set  to  be  the 
correct  one ;  it  is  impossible  to  set  the  tooth  too 
far.  The  steel  is  condensed,  and  the  tooth  is 
drawn  out,  rather  assisting  the  file  than  other- 
wise. ____... - .-^^"-^^., 


Setting  mill  and  other  large  saws,  as  at  Figs. 
84  and  35. — Large  and  heavy  saws  are  set  now 


THE  ART  OF  SAW-FILING. 


55 


with  the  crotch-punch,  which  is  represented  at 
Fig.  44. 


/\     /X 


Fig.  44. 

This  punch  is  made  of  steel,  and  very  hard 
in  the  fork,  where  it  comes  in  contact  with  the 
point  of  the  tooth.  The  teeth  are  not  bent  but 
spread  out  or  upset,  as  shown  at  Fig.  33. 

This  is  no  doubt  the  best  way  to  set  large 
and  heavy  saws,  it  being  very  dif&cult  to  bend 
the  teeth  of  a  thick  saw  regularly.  Great  care 
must  be  taken  with  this  set  to  have  the  teeth 


66  THE  AKT  OF  SAW-FILING. 

spread  even  and  regularly ;  and  they  should 
be  jointed  on  both  sides  and  tried  with  a 
straight  edge,  and  also  on  the  points,  so  that 
every  tooth  shall  be  exactly  in  line  with  the 
others.  If  only  one  tooth  stands  out  more  than 
the  others,  it  causes  a  waste  of  power  and  makes 
rough  work  besides. 

The  old  way  of  setting  mill-saws,  with  an 
axe  and  hammer,  is  very  bad.  True,  a  saw 
"will  saw  set  in  this  way  by  sheer  force ;  but 
if  set  the  right  way,  one-third  less  power  ^vill 
do  the  work,  and  consequently  one- third  more 
speed  may  be  obtained. 

In  conclusion,  we  would  say  in  selecting 
saws,  as  in  all  other  tools,  always  get  the  best, 
even  at  higher  prices ;  a  good  tool  will  always 
give  satisfaction  to  the  buyer,  while  a  poor  one 
is  dear  at  any  price. 

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